1. Field of the Invention
The present invention relates to a portable respiration apparatus, particularly a portable ventilator of the type having a pressure and flow generating unit with an inlet, and an outlet connectable to a patient.
The present invention also relates to a respiration apparatus system.
2. Description of the Prior Art
Simple types of ventilators (home care ventilators) intended for use in the home are available for many patients in need of limited assisted ventilation. These home ventilators often contain a compressor or fan for generating the required pressure of air supplied to the patient and sometimes even a small oxygen cylinder for enriching the oxygen content of the supplied air. Ventilators of this kind are also used in hospitals for e.g. subacute patients and in many developing countries. Utilization of these ventilators makes it possible to prevent the unnecessary occupation of expensive beds in intensive care.
One problem with these ventilators is the fact that they are relatively large and heavy, since a relatively large fan/compressor is needed to generate the full range of pressures that may be needed in treatment, i.e. up to about 100 cm H.sub.2 0. They also consume large amounts of energy. When the ventilators are battery-powered, the battery also contributes to increased ventilator weight and bulk. Even if they are transportable, usually mainly by being installed on different kinds of wheeled carriers, they are not particularly suitable for being carried by the patient.
A completely portable respiration apparatus would therefore offer the patient enormous freedom. One such apparatus can be achieved by miniaturizing the fan and by limiting the gas pressure that the apparatus is able to generate in relation to the available energy (a battery), e.g. by limiting pressure to about 40 to 60 cm H.sub.2 0. This pressure is sufficient for most patients in this category, especially patients who do not require supplemental oxygen or only a very small amount of supplemental oxygen (enabling a very small cylinder to last a relatively long time). The fan can then be completely battery-powered, and a smaller (rechargeable) battery will last long enough for the patient to be away from her/his home safely for a few hours, e.g. to go shopping or visit the doctor. When the patient returns home, or the battery needs recharging, the portable respiration apparatus is simply plugged into the nearest source of electrical power, such as the public mains (wall socket) or a car battery. The patient thus has almost unlimited mobility when traveling by car.
It should also be noted that the pressure-generating part of the portable respiration apparatus has a limited supply of energy, not necessarily a limited pressure-generating capacity. Miniaturization is solely for the purpose of minimizing battery size while still achieving a reasonably long period of time during which the portable respiration apparatus is able to run on battery power. When the portable respiration apparatus is used without any other source of energy except the battery for very brief periods of time, the portable respiration apparatus can be allowed to consume more energy and, accordingly, it can generate a higher pressure.
Nonetheless, even greater safety would be desirable to cover 30 every conceivable eventuality in which the supply of energy is limited or when the pressure-generating part of the respiration apparatus is technically restricted to the generation of a particular pressure, e.g. 40-60 cm H.sub.2 0.
In the latter instance, there is also the problem of accommodating patients in temporary need of a gas pressure higher than the portable ventilator is able to deliver.
One way to solve this problem would be to equip each patient with both a conventional home care ventilator and a portable respiration apparatus, however, the patient would then be forced to switch tubing to her/his airways and/or to the apparatus currently being used, as well as having to program both devices. This arrangement would also be more expensive overall, since both devices would have to be capable of independent operation.